Desensitizing apparatus for offset-press



United States Patent Kohichl Hirokawa Inventor Tokyo, Japan Appl. No. 742,429 Filed July 3, 1968 Patented Dec. 1, 1970 Assignee Kabushlki Kalsho Ricoh Tokyo, Japan a corporation of Japan Priority July 8, 1967 Japan DESENSITIZING APPARATUS FOR OFFSET- PRESS 1 Claim, 2 Drawing Figs.

Int. Cl. 84" 35/00 Field ofSearch 101/147,

364, 423, 425; 118/(lnquired), 243, 263

References Cited UNITED STATES PATENTS 2,798,426 7/1957 .lanke et al 2,113,690 4/1938 HarringtonJr. 3,043,215 7/ 1962 Gates.

3,084,626 4/1963 Stobb.

Primary ExdminerRobert E. Pulfrey Assistant ExaminerEugene H. Eickholt Attorney-Burgess, Ryan and Hicks ABSTRACT: There is provided a desensitizing apparatus 'for use with a rotary offset press which functions to apply desensitizing liquid to sheet material. in particular, the coating surface of the liquid applicator is at all times, i.e., during use and at rest, maintained in a downwardly facing position, no reversal of such surface being permitted.

DESENSITIZING APPARATUS OFFSET-PRESS BRIEF DESCRIPTION OF DRAWINGS FIG. -1 is a side elevational view of a desensitizing apparatus illustrating one embodiment of the invention, and 3 FIG. 2 is a top plan view of the same.

DESCRIPTIQN OF THE PREFERRED EMBODIMENT Referring to the drawings, numeral 1 designates a side plate of the rotary offset press, 2 is a plate cylinder which supports the original sheet material, and 3 is a form roller.

A supporting plate 5, having a guide groove 4 therein, is disposed inside of said side plate 1 and is supported thereon by the support members 6; A gear wheel 9a is fixed to one end of an operating lever 8, the latter being pivotally engaged with the spindle 7 which extends between said side plate and the supporting plate 5, and this gear 9a is engaged with a pinion 9b fixed at the end of the spindle l0.

Spindle 10 is rotatably supported on plate and on a companion supporting plate (not shown). A spring (not shown) biasses spindle in a counterclockwise direction.

A frame 12 encloses the upper portion of a bar-shaped desensitizing liquid coating element 11 of high absorbent power. The frame has a short shaft 14 extending from its end to which one end of a supporting arm 13 is pivotally attached. The spindle 14 is also pivotally engaged by one end of a rotatable arm 15, the other end of which is pivoted to plate 5 through the spindle 10; in other words, the arm 15 rotates with spindle 10. Thus, lever 8 operatively engages the arm 15 through the medium of gear 9a, pinion 9b, and spindle 10, and is effective to rotate such arm about its pivot on plate 5. A roller 16 is attached to the free end of supporting arm 13 and is pivotally engaged in said guide groove 4. The roller is also adapted to move in said groove.

The lower coatingsurface of the coating element 11 is dipped in the desensitizing liquid bath contained in a pan 18 suitably supported against the supporting plate 5. The pan 18, it may be noted, is disposed above the cylinder 2 and also above the spindle 10, and the coating surface of element l1 faces downwardly in its rest position.

After winding the original sheet material on the plate cylinder 2, and turning the operating lever 8 about the spindle 7 in the direction of the arrow, the arm 15 is rotated in a clockwise direction. In turn, the supporting arm 13 moves to the right, as seen in FIG. 1, being guided by the engagement of roller 16 in guide groove 4. As the operating lever 8 is rotated to the position shown by dashed line A, the arm 15 and coating element 11 assume the position shown by dashed line A', and will be noted that the coating surface of element 11 faces downwardly. As said lever 8 is moved to a final position, as shown by dashed line B, said arms 13 and 15 take positions shown by dashed line B, and the coating surface of element 11, now designated 11', still faces downwardly as it makes contact with the sheet on the cylinder 2. Thus, the coating surface makes effective contact with the sheet without being reversed at any time.

lclaim:

1. A desensitizing apparatus for use with a rotary offset press comprising a plate cylinder for supporting sheet material, a desensitizing liquid bath disposed thereabove, a coating element in said bath having an absorbent coating surface facing downwardly therein in contact with bath liquid, a supporting plate disposed at one side of said cylinder and bath, a guide groove in said plate, a rotatable arm pivoted to said plate and having an end that is pivotally connected to said coating element, a supporting arm having one end pivotally connected to said coating element and at its other end having a roller for pivotally engaging said guide groove, said roller also being movable in said groove, a lever operatively engaging said rotatable arm and effective to rotate the latter about said plate pivot thereof, said rotation of the rotatable arm, in conjunction with the movement of said supporting arm, serving to lift the coating element out of the bath and swing the same around said plate pivot and downwardly toward said sheet material while maintaining said coating surface in a downwardly facing position throughout said lifting and swinging movement, and said coating surface making contact with said sheet material to apply desensitizing liquid thereon. 

